Volume 23 Issue 10, Pages 1361-1369 (30 July 2008)
Published Online: 10 June 2008
Authors: Laurence Nègre-Pagès, PhD, Wafa Regragui, MD, Didier Bouhassira, MD, Héléne Grandjean, MD, Olivier Rascol, MD, PhD , on behalf of the DoPaMiP Study Group (Investigators listed at end of report)
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Pain is a frequent, but poorly studied symptom of Parkinson's disease (PD). DoPaMiP survey aimed to assess the prevalence of chronic pain in PD, to describe PD patients with chronic pain, and to record analgesic consumption. About 450 parkinsonian patients underwent structured standardized clinical examination and completed self-reported questionnaires in a cross sectional survey. Pains related or unrelated to PD were identified according to predefined criteria. About 98 patients with other chronic disorders than PD were examined to assess if pain was more frequent in PD than in this population. Two thirds parkinsonian patients (278 of 450) had chronic pain. Twenty-five patients with non-chronic pain (<3-month duration) were excluded from subsequent analysis. Twenty six percent (111 of 425) parkinsonian patients had pain unrelated to PD ( non-PD-pain , caused mainly by osteoarthritis), while 39.3% (167 of 425) had chronic pain related to PD ( PD-pain ). In this last group, PD was the sole cause of pain in 103 and indirectly aggravated pain of another origin (mainly osteoarthritis) in 64. Parkinsonian patients with PD-pain were younger at PD onset, had more motor complications, more severe depressive symptoms than those without pain or with non-PD pain. PD-pain was more intense (P = 0.03), but was less frequently reported to doctors (P = 0.02), and was associated with less frequent analgesic consumption than non-PD-pain. Pain was twice more frequent in PD patients than in patients without PD after adjustment for osteo-articular comorbidities (OR = 1.9; 95% CI 1.2-3.2). Chronic pain is frequent but underreported in PD. Awareness of this problem should be increased and the assessment of analgesic strategies improved.
© 2008 Movement Disorder Society
Podcast review by Professor Sergio Starkstein, MD, PhD, University of Western Australia
Pain is one of the most common non-motor problems of Parkinson’s disease (PD). Nevertheless there is a paucity of appropriate epidemiological studies on the prevalence, clinical correlates and main predictors of pain in PD. This is of great clinical relevance, given that pain is associated with poor health-related quality of life in PD.
Negre-Pages and co-workers carried out the most comprehensive study on pain in PD. The study included 450 patients with PD attending outpatient neurology clinics and 98 age-comparable individuals without PD from a specifically defined region in France. Patients were assessed with instruments assessing pain both objectively (e.g. The Brief Pain Inventory, the McGill Pain questionnaire), as well as with subjective interviews that categorized pain into “non-PD” and “PD-related” (i.e. pain caused or aggravated by PD).
The most relevant finding was that about two-thirds of PD patients reported chronic pain. Twenty-six percent of patients had chronic pain unrelated to PD, mostly associated to osteoarthritis, whilst 39% had chronic pain related to PD (many of them with pain aggravated by osteoarthritis). The authors managed to identify a subgroup of patients with pain caused by PD (e.g. “off” dystonia, neuropathic-like, related to akathisia) which was relatively younger at PD onset, had more frequent motor complications, and more severe depression that PD patients without PD-related pain. PD-pain was less frequently reported to doctors, was more intense, but paradoxically, was associated with less frequent analgesic consumption than “non-PD related” pain.
In conclusion, this is the largest study of pain in PD and replicated previous findings of a high frequency of this clinically relevant non-motor symptom. The authors commented on the difficulty of ascribing pain to PD and to other pain-inducing complications in the elderly. Nevertheless, the authors identified a sub-group of patients whose pain seems to be related to PD factors only. The challenge for future studies is to determine whether pain is related to peripheral factors (e.g. mechanical factors) and/or to central non-dopaminergic factors. The role of depression to produce or enhance the severity of pain should also be examined.
About Prof. Sergio Starkstein, MD, PhD
Professor Starkstein is Head of the Neuropsychiatric Unit, School of Psychiatry, at the University of Western Australia, and Head of Clinical-Liaison Psychiatry, Fremantle Hospital at Fremantle, Australia. He is a member of the Task Force commissioned by The Movement Disorder Society to assess psychometric properties of scales used to measure depression, apathy, anxiety and anhedonia in Parkinson’s disease (PD). He is the Principal Investigator of an ongoing study to examine the genetic and brain metabolic correlates of depression and apathy in PD, and is a Co-Investigator of a project recently funded by the Michel J. Fox Foundation to empirically assess the psychometric qualities of anxiety scales in PD.